Synchronous interface to asynchronous processes

ABSTRACT

Methods, apparatus, and computer program products are disclosed for facilitating access to one or more services in a network environment. At a host, a request is received from a client machine in communication with the host over a network. An asynchronous service description file indicates one or more asynchronous communication techniques configured to be performed to access or communicate with a service over the network. The asynchronous service description file is a conversion of a synchronous service description file indicating one or more synchronous communication techniques for accessing or communicating with a synchronous service. The asynchronous service description file is provided to the client machine.

CROSS-REFERENCE TO RELATED APPLICATIONS

The present application is a continuation of and claims priority under35 U.S.C. §120 to U.S. patent application Ser. No. 13/563,365 forSYNCHRONOUS INTERFACE TO ASYNCHRONOUS PROCESSES, filed Jul. 31, 2012,which is a continuation of and claims priority under 35 U.S.C. §120 toU.S. Pat. No. 8,260,849 for SYNCHRONOUS INTERFACE TO ASYNCHRONOUSPROCESSES, filed May 10, 2010, which is a continuation of and claimspriority under 35 U.S.C. §120 to U.S. Pat. No. 7,739,351 for SYNCHRONOUSINTERFACE TO ASYNCHRONOUS PROCESSES, filed Mar. 23, 2004, the entiredisclosures of which are hereby incorporated by reference for allpurposes.

BACKGROUND

The present invention relates to techniques for enabling communicationbetween synchronous and asynchronous processes. More specifically, thepresent invention enables interaction between synchronous andasynchronous web services in a network environment.

The web service provider market is one of the fastest growing segmentsof the software industry. Web service providers make enterpriseapplications, such as human resources administration, recruiting, traveland expense management, sales force automation, and so on, available tocustomers over the web on a subscription basis, or for free. Theseenterprise applications are fully managed and hosted by the web serviceproviders, which results in significant cost savings for enterprisesusing the web services and eliminates many of the issues requiringindividual enterprise application integration (EAI) solutions.

Some web service providers merely host and manage third-party packagedsoftware for their customers (i.e., “managed hosters”). Others build newapplications from the ground up to take advantage of the benefits andcost-savings of the web service provider model. Web service providersenjoy the profit margins and operational scalability of consumer Webcompanies like eBay and Yahoo, while at the same time offering thefeature sets of complex enterprise software applications such asPeopleSoft and Siebel.

Client applications can locate the web services using a UDDI (UniversalDescription, Discovery, and Integration) service, which is based on XML(eXtended Markup Language) and SOAP (Single Object Access Protocol). XMLis a markup language for documents containing structured information,that is, the information and an indication of its role, and is a commonway to provide information over wide area networks, such as theInternet. SOAP is an XML-based protocol for exchanging information in adecentralized, distributed environment. SOAP can be used in combinationwith a variety of protocols, but its most frequent use is in conjunctionwith HTTP (Hyper Text Transfer Protocol). Web service providers canregister contact addresses and descriptions of the provided web servicesin a UDDI directory, and prospective clients can use the UDDI directoryas a “phone book for web services,” and look up web services that fitthe clients' needs.

Web services are typically described in a Web Service DescriptionLanguage (WSDL), which is an XML-based format. WSDL enables separationof the description of the abstract functionality offered by a webservice from concrete details of a service description, such as “where”and “how” the functionality is offered. WSDL describes web servicesstarting with the messages that are exchanged between the web serviceprovider and a requestor. The messages are first described abstractlyand are then bound to a concrete network protocol and message format. Amessage consists of a collection of typed data items. A message exchangebetween the web service provider and the requestor is referred to as anoperation. A collection of operations is a portType. Collections ofportTypes are grouped and referred to as a service. A web servicerepresents an implementation of a service and contains a collection ofports, where each port is an implementation of a portType, whichincludes all the concrete details the requestor needs in order tointeract with the web service.

Two main communication models exist for communication between arequestor and a web service: a synchronous communication model and anasynchronous communication model. In the synchronous communicationmodel, a requestor communicates synchronously with a synchronous webservice, that is, the requestor sends a request to the web service andwaits until a response is returned. The requestor is prevented fromperforming any other operations until the response is received.

In the asynchronous communication model, on the other hand, a requestorcommunicates asynchronously with a web service, that is, the requestorsends a request to the web service, some time may pass, and a responseis returned by the web service. The requestor may perform otheroperations while waiting for the response from the web service.Currently, the two communication models cannot work in conjunction, andas a consequence there is no way for a synchronous requestor tocommunicate directly with an asynchronous web service, or for anasynchronous requestor to communicate directly with a synchronous webservice.

SUMMARY

In general, in one aspect, the invention provides methods and apparatus,including computer program products, implementing and using techniquesfor enabling communication between synchronous and asynchronousprocesses. One or more web services are selectively accessed from aclient machine over a network. A request for information is receivedfrom a client machine with a conversion engine. The request is receivedover a synchronous interface. The request is processed in the conversionengine, and the processed request is transmitted over an asynchronousinterface from the conversion engine to at least one web service.

Advantageous implementations can include one or more of the followingfeatures. The network can be a local area network or a wide areanetwork. A response to the processed request can be received from the atleast one web service with the conversion engine over the asynchronousinterface, be processed in the conversion engine, and be transmittedover the synchronous interface from the conversion engine to the clientmachine. Receiving a request can include blocking the client machineuntil a response to the received request has been obtained from the webservice and delivered to the client machine, until an error message hasbeen delivered to the client machine, or until a predetermined timeperiod has passed. Processing the request can include receiving therequest at a synchronous post interface, placing the request in areceive queue, routing the request to one or more delivery queues, andtransferring the request from the delivery queues to one or moreasynchronous push interfaces.

A confirmation can be received from the at least one web service overthe asynchronous interface that the processed request has been receivedby the at least one web service. Transmitting the processed request caninclude pushing the processed request to the at least one web serviceover the asynchronous interface, or transmitting an available processedrequest to the at least one web service through the asynchronousinterface in response to polling of the asynchronous interface by the atleast one web service. Processing the request can include performingsecurity management including authentication, authorization, securitypolicy enforcement, decryption, or validation of digital signatures.Processing the response can include receiving the response at anasynchronous post interface, placing the response in a receive queue,and routing the response to a delivery queue for the client machine.

A confirmation can be transmitted to the at least one web service overthe asynchronous interface that the response has been received by theconversion engine. Transmitting the processed response can includepushing the processed response to the client machine over thesynchronous interface.

In general, in one aspect, the invention provides a conversion engine.The conversion engine has a synchronous interface, an asynchronousinterface, and a processing module. The synchronous receives a requestfrom a client machine communicating synchronously with the conversionengine over a network and delivers a response to the request from theconversion engine to the client machine over the wide area network. Theasynchronous interface delivers the received request from the conversionengine to one or more web services communicating asynchronously over thewide area network, and receives a response to the request from the oneor more web services over the wide area network. The processing moduleconverts a synchronous request into an asynchronous request, and

converts an asynchronous response into a synchronous response.

Advantageous implementations can include one or more of the followingfeatures. The conversion engine can include a routing module that routesa received request to one or more web services, and routes a receivedresponse to the request to the client machine. The conversion engine caninclude a policy directory storing policies for performing securitymanagement including one or more of: authentication, authorization,security policy enforcement, decryption, and validation of digitalsignatures. The conversion engine can include a web service directorycontaining information about available web services and theircommunication interfaces, for example, in the form of one or more webservice description language files.

In general, in one aspect, the invention provides methods and apparatus,including computer program products, implementing and using techniquesfor

converting a first web service description language file describingsynchronous operations for a web service into a second web servicedescription language file describing asynchronous operations. A firstweb service description language file describing synchronous operationsfor a web service is provided to a conversion engine. The first webservice description language file is translated in the conversion engineinto a second web service description language file describingasynchronous operations. The second web service description languagefile is provided to the client machine for further generation of clientmachine code.

Advantageous implementations can include one or more of the followingfeatures. Translating can include one or more of the followingoperations: translating a types part of the first web servicedescription language file into a types part of the second web servicedescription language file, translating a message part of the first webservice description language file into a message part of the second webservice description language file, translating a port type part of thefirst web service description language file into a port type part of thesecond web service description language file, translating a bindingspart of the first web service description language file into a bindingspart of the second web service description language file, andtranslating a service part of the first web service description languagefile into a service part of the second web service description languagefile.

Translating a types part can include preserving any data structuresdefined in the first web service description language file in the secondweb service description language file. Translating a types part caninclude adding an acknowledge element in the asynchronous web servicedescription language file, the acknowledge element describing anacknowledgement that is returned when a request is asynchronously postedto the conversion engine by the client machine. The acknowledgement caninclude a correlation identifier, which can be a session identifier, atoken, or a call identifier.

Translating a message part can include adding messages to theasynchronous web service description language file that are particularto asynchronous communication, including one or more of: a message forreturning an acknowledgement response, a message for polling, a messagefor acknowledging a received request, and a message for acknowledging aresponse from a web service. The message for polling can include one ormore of: a message for polling using a session identifier, a message forpolling using a topic, and a message for polling using a token.Translating a port type part can include inserting a port type forasynchronous post operations and a port type for asynchronous polloperations into the second web service description language file. Theport type can contain one or more of the following polling options:polling by session identifier, polling by topic, and polling by token.

Translating a bindings part can include inserting binding for a postport type, inserting a binding for a poll port type, and setting anencoding for messages that include the port types to reflect theencoding used by the conversion engine. Translating a service part caninclude adding an asynchronous post port with a first uniform resourcelocator addressing the conversion engine, and an asynchronous poll portwith a second uniform resource locator to the conversion engine. Atemplate stored in the conversion engine can be used for translating atleast part of the synchronous web service description language file intothe asynchronous web service description language file.

In general, in one aspect, the invention provides methods and apparatus,including computer program products, implementing and using techniquesfor converting a first web service description language file describingasynchronous operations for a web service into a second web servicedescription language file describing synchronous operations. A first webservice description language file describing asynchronous operations fora web service is provided to a conversion engine. The first web servicedescription language file is translated in the conversion engine into asecond web service description language file describing synchronousoperations. The second web service description language file is providedto the client machine for further generation of client machine code. Theinvention can be implemented to include one or more of the followingadvantages. Requestors and web services can communicate with each otherregardless of which communication model they support. For example, asynchronous requestor can communicate directly with an asynchronous webservice. Similarly, an asynchronous requestor can communicate directlywith a synchronous web service. This enables requestors to access awider range of web services, hosting services both specific to therequestors' respective enterprises, as well as common applicationservices, such as doing a customer credit check, neither of which therequestors need to create nor maintain.

The ability to communicate with web services, irrespective of theirrespective communication models, facilitates information and servicesexchange between enterprises. For example, two enterprises can accessthe same web service network, where they have access to commoninformation and services. This, in turn, facilitates inter-enterpriseprocesses such as assuring that there are enough raw materials availableto build a certain product. More enterprise application functions can behosted by web services and accessed on a subscription basis, instead ofwithin the requestor's own enterprise, which may lead to significantcost savings. WSDL files describing synchronous web services can beconverted into asynchronous WSDL files that can be used by asynchronousrequestors to communicate with the synchronous web services, without therequestors having to know that they are communicating with synchronousweb services. Use of asynchronous services may ease implementation ofparallel data processing.

The details of one or more embodiments of the invention are set forth inthe accompanying drawings and the description below. Other features,objects, and advantages of the invention will be apparent from thedescription and drawings, and from the claims.

DESCRIPTION OF DRAWINGS

FIG. 1 shows a schematic diagram of a system in which the invention canbe implemented.

FIG. 2 shows a schematic diagram of how a synchronous requestorcommunicates through an integration services network with anasynchronous web service.

FIG. 3 shows a schematic diagram of how an asynchronous requestorcommunicates through an integration services network with a synchronousweb service.

Like reference symbols in the various drawings indicate like elements.

DETAILED DESCRIPTION

The invention will now be described by way of example with reference tospecific implementations that are illustrated in the accompanyingdrawings. While the invention is described in conjunction with thesespecific implementations, it will be understood that this description isnot intended to limit the invention to the described implementations. Onthe contrary, this detailed description is intended to coveralternatives, modifications, and equivalents as may be included withinthe spirit and scope of the invention as defined by the appended claims.

FIG. 1 shows a schematic diagram of a system (100), in which theinvention can be implemented. As can be seen in FIG. 1, the system (100)includes a requestor (102), or client, that uses a synchronouscommunication model to access web services, and a requestor (104), orclient, that uses an asynchronous communication model to access webservices. The system further includes a web service (108) that isconfigured to be accessed asynchronously, and a web service (110) thatis configured to be accessed synchronously. It should be noted that onlytwo requestors and two web services are shown for simplicity. In atypical situation, typically, many web services and many requestors arepresent.

The system (100) further includes an integration services network (106),for enabling the requestors (102; 104) to communicate with the webservices (108; 110) irrespective of the communication methods supportedby the individual requestors and web services. The integration servicesnetwork (106) is accessible for the requestors (102; 104) and the webservices (108; 110) over a local area network, such as an intranet, orover a wide area network, such as the Internet. The integration servicesnetwork (106) facilitates interoperability using a wide variety of webservices technologies and standards including, for example, SOAP, WSDL,WS-Security, WS-Policy, and Business Process Execution Language (BPEL),and mediates the technology differences in data formats, communicationsprotocols and business policies through a set of established and definedpolicies. The system (100) can be either an “open system” or a “closedsystem.” In an open system, typically, the requestors (102; 104) and webservices (108; 110) are owned and/or managed by entities distinct fromeach other and distinct form the owner of the integration servicesnetwork (106). In the closed system, the requestors (102; 104) and webservices (108; 110) are typically owned and/or managed by the owner ofthe integration services network (106). Combinations of open and closedsystem are also possible, in which there are some commonly owned and/ormanaged components, and some components that are owned and/or managed bydifferent entities.

As can be seen in FIG. 1, the integration services network (106)contains a message (112) that is sent from a requestor (102; 104) to aweb service (108; 110) through the integration services network (106).The message can, for example, be a request for information that is sentby a specific requestor (102) to a specific web service (108) that ishosted at a remote location.

In some implementations, the integration services network (106) can alsospecify which requestors (102; 104) have permission to access the webservices (108; 110). For example, the integration services network (106)can provide security management including authentication, authorizationand security policy enforcement at various points in a message's (112)lifecycle inside the integration services network (106), for example,when a message (112) is sent into the integration services network (106)from a requestor (102; 104), and when the message (112) is routed to itsdestination web service (108; 110). In one implementation, the policiesneeded for the integration services network (106) to perform securitymanagement operations are stored securely in a policy repository (116)in the integration services network (106). According to variousimplementations, the requestors (102; 104) and the providers of the webservices (108; 110) need not be aware of the message format requirementsof the party to which the message (112) is sent, nor of any messageformat translation taking place in the integration services network(106). A more detailed discussion of exemplary processes for mediatingmessages between the synchronous and asynchronous communication formatsis provided below with reference to FIGS. 2 and 3.

In addition to providing mechanisms for mediating messages (112) sentbetween requestors (102; 104) and web services (108; 110), theintegration services network (106) also preferably includes a webservice directory (114) for storing various information regarding theweb services (108; 110) that are accessible through the integrationservices network (106). Such information may include, for example,information similar to the UDDI information, which facilitates locatingweb services (108; 110) for requestors (102; 104), WSDL files for thedifferent web services (108; 110), and policies that control whichrequestors (102; 104) and web services (108; 110) may interact, and howthe interaction occurs. The integration services network (106)preferably also includes mechanisms for creating and combining webservices (108; 110), registering requestors (102; 104) and theiridentifying information, and handling messages (112) routed between webservices (108; 110) and/or requestors (102; 104). The directory (114)may be created from one or more databases stored on one or more memorydevices on one or more computing platforms. Implementations of theintegration services network (106) can also include components enablingcomplex routing and business process management, which both have beendescribed in the above-referenced patent applications.

FIG. 1 has been described with reference to web services. However, itshould be clear that the concepts described above can be applied to anytype of “service,” such as any computer application, process, entity, ordevice accessible to other applications, processes, entities, or devicesthrough an interface such as an application programming interface (API),user interface, or Internet web user interface by any of a variety ofprotocols over a network within an entity or over the Internet. Aservice can also include multiple methods or applications on a singledevice or distributed across multiple devices.

Additional mechanisms and techniques for provisioning services and forenabling disparate entities to interact according to the invention aredescribed in U.S. patent application Ser. Nos. 09/820,964, 09/820,966,10/727,089, 10/728,356 and 10/742,513 incorporated herein by referenceabove. Any of the mechanisms described in these referenced applicationscan easily be applied with the techniques described herein.

Two exemplary scenarios will now be described with reference to FIGS. 2and 3. In the first scenario, which is illustrated in FIG. 2, animplementation is shown in which a requestor (102) that supports onlysynchronous communication sends a request to the integration servicesnetwork (106), which forwards the request to and receives a responsefrom a web service (108) that supports only asynchronous communication.In the second scenario, which is described in FIG. 3, an implementationis shown in which a requestor (104) that supports only asynchronouscommunication sends a request to the integration services network (106),which forwards the request to and receives a response from a web service(110) that supports only synchronous communication. The scenarios inwhich a synchronous requestor (102) communicates with a synchronous webservice (108), and in which an asynchronous requestor (104) communicateswith an asynchronous web service (110), are well described in the art aswell as in the above-referenced patent applications, and will thereforenot be discussed herein. In one implementation, the operations that willbe described below are performed by a conversion engine, which formspart of the integration services network (106) and is dedicated toperforming operations for connecting synchronous requestors withasynchronous web services, and asynchronous requestors with synchronousweb services, respectively.

As can be seen in FIG. 2, a request to obtain information from anasynchronous web service (108) is sent by a synchronous requestor (102).The request is posted to a synchronous post interface (202) in theintegration services network (106). The synchronous post interface (202)can, for example, be a SOAP over HTTP interface, or a HTTP Getinterface. It should be noted that such an interface can also be usedfor the integration services network's (106) asynchronous interfaces.The difference, as will be seen below, is that for a synchronousinterface, the requestor (102) and integration services network (106)agree that the requestor (102) will block until the integration servicesnetwork (106) synchronously returns a response. For an asynchronousinterface, on the other hand, the requestor (102) and the integrationservices network (106) agree that the integration services network (106)will only synchronously return an acknowledgement, and then theintegration services network (106) will later make a response availableasynchronously. The format of the posted request is identical to arequest that would otherwise be posted directly to a synchronous webservice. The synchronous post interface (202) blocks the request andplaces the request in a receive queue (204). In one implementation theposting of the request establishes an HTTP session between thesynchronous requestor (102) and the integration services network (106).The synchronous requestor now waits until a response is delivered backfrom the integration services network (106). The request is thenretrieved from the receive queue (204) and routed (206) to one or moredelivery queues (208). Typically there is one delivery queue (208) foreach web service (108) to which the request should be sent. Forsimplicity, only one delivery queue (208) is shown in FIG. 2. In oneimplementation, the routing is performed by a message router in theintegration services network (106), and the message router also performsa security policy and permission verification to verify that therequestor (102) is allowed to send requests to the web service (108) inquestion, and that the request has the proper format. In someimplementations, complex routing, for example, rule-based routing, asdescribed in the above-referenced patent applications, can be used. Theintegration services network (106) then retrieves the request from thedelivery queue and pushes (210) the request out to the web service (108)that is associated with the delivery queue. The push delivery of therequest is similar to what would have occurred had the requestor (102)been an asynchronous client and invoked the web service (108) directly.The asynchronous web service (108) receives, acknowledges, and processesthe request. It should be noted that in one implementation theasynchronous web service (108) does not return a response synchronouslyto the received request, since this would be interpreted only as adelivery acknowledgement and not a response. Any responses from theasynchronous web service (108) are instead posted separately to theintegration services network (106), as will be seen below.

When the asynchronous web service (108) is done processing the requestand has generated a response, the response is posted asynchronously to apost interface (212) in the integration services network (106). As wasdiscussed above, this post interface (212) can, for example, be a SOAPover HTTP interface, or a HTTP Get interface. Just like when a requestis sent, the format of the posted response is identical to a responsethat would otherwise be posted directly to an asynchronous requestor, sothe asynchronous web service (108) does not have to be aware of that therequestor (102) is asking for a synchronous response. The response caneither be posted to the network by the web service, which is alsoreferred to as pushing the request, or the integration services network(106) can poll the asynchronous web service (108) for a response. If theposting was successful, the post interface (212) returns a confirmationto the web service (108), and places the request in a receive queue(214). If the posting is unsuccessful, the post interface (212) returnsan error, and the web service (108) attempts to post the response againat a later time. After successful posting and delivery to the receivequeue (214), the response is retrieved from the receive queue (214) androuted (216) to a delivery queue (218) for the synchronous requestor(102). The post interface (202) continuously polls the delivery queue(218) to determine whether any responses have been posted to thedelivery queue (218). When a response is detected in the delivery queue(218), the response is returned to the synchronous requestor (102) andthe process ends.

From the synchronous requestor's (102) side, it appears as if theasynchronous web service (108) is a synchronous web service, since thesynchronous requestor is not aware of any operations that occur withinthe integration services network (106). All the synchronous requestor(102) sees is a request being sent out, blocked, and a response returnedafter some time has passed. It should be noted that otherimplementations are also possible. For example, the asynchronous webservice (108) could use a polling interface instead of the pushinterface (210) to accept requests.

Turning now to the second scenario, which is described in FIG. 3, animplementation is shown in which a requestor (104) that supports onlyasynchronous communication sends a request to the integration servicesnetwork (106), which forwards the request to and receives a responsefrom a web service (110) that supports only synchronous communication.As can be seen in FIG. 3, a request to obtain information from asynchronous web service (110) is sent by an asynchronous requestor(104). The request is posted to an asynchronous post interface (302) inthe integration services network (106), such as a SOAP over HTTPinterface, or a HTTP Get interface. The format of the posted request isidentical to a request that would otherwise be posted directly to anasynchronous web service. If the posting was successful, theasynchronous post interface (302) returns a confirmation to theasynchronous requestor (104), and places the request in a receive queue(304). If the posting is unsuccessful, the asynchronous post interface(302) returns an error, and the requestor (104) attempts to post therequest again at a later time. After successful posting and delivery tothe receive queue (304), the request is retrieved from the receive queue(304) and routed (306) to one or more delivery queues (308). Again,typically there is one delivery queue (308) for each web service (108)to which the request should be sent, but for simplicity, only onedelivery queue (308) is shown in FIG. 3. Also here, the routing can beperformed by a message router in the integration services network (106),which may also perform a security policy and permission verification toverify that the requestor (104) is allowed to send requests to the webservice (110), and ensure that the request has the proper format. Theintegration services network (106) then retrieves the request from thedelivery queue and pushes (310) the request out to the web service (110)that is associated with the delivery queue (308). The push delivery ofthe request is much like as if the requestor (104) had invoked the webservice (110) directly. The pushing of the request establishes an HTTPsession between the synchronous web service (110) and the integrationservices network (106).

When the synchronous web service (110) is done processing the requestand has generated a response, the response is synchronously returned tothe push interface (312), for example, a SOAP over HTTP interface, or aHTTP Get interface, in the integration services network (106) on thesame HTTP session that the request was delivered on, and the HTTPsession between the integration services network (106) and thesynchronous web service (110) is terminated. Just like when a request issent, the format of the response is identical to a response that wouldotherwise be returned directly to a synchronous requestor, so thesynchronous web service (110) does not have to be aware of that therequestor (104) requires an asynchronous response. The returned responseis delivered to a receive queue (314) and routed (316) to a deliveryqueue (318) for the asynchronous requestor (104).

The asynchronous requestor continuously polls (320) the delivery queue(318) to determine whether any responses have been posted to thedelivery queue (318). When a response is detected in the delivery queue(318) through the polling operation (320), the response is returned tothe asynchronous requestor (104), which acknowledges the returnedresponse, and ends the process. From the asynchronous requestor's (104)side, it appears as if the synchronous web service (110) is anasynchronous web service. It should be noted that other implementationsare also possible. For example, a push interface could be used insteadof the poll interface (320) to supply responses to the requests to theasynchronous requestor (104).

As was described above, WSDL is an XML-based description of how toconnect to and communicate with a particular web service. A WSDLdescription abstracts a particular service's various connection andmessaging protocols into a neutral interface description and forms a keyelement of the UDDI directory's service discovery model. A WSDL filetypically has five different parts: a types part, a message part, a porttype part, a bindings part, and a service part. The types part is usedto define data structures, the messages part is used to define one ormore messages, the port type part is used to define how messages will begrouped together into operations, the bindings part is used to defineencoding and placement of message parts, and the service part is acollection of ports consisting of a binding and a network address (orURL) for the web service. Many synchronous web services use WSDL todescribe the web service. When a synchronous requestor would like tosynchronously invoke a synchronous web service, the requestor can obtainthe WSDL file describing the synchronous web service, bring the WSDLfile into their computer system, which parses the WSDL file andgenerates code on the requestor's computer system that can properlyinvoke the synchronous web service. However, as was seen in FIG. 3, manyrequestors communicate asynchronously and can therefore not benefit fromthe WSDL files that are designed for synchronous communication.

The invention solves this problem by translating a WSDL file publishedby a synchronous web service (110) with the integration services network(106) into a WSDL file that can be used by an asynchronous requestor. Inone implementation, the translation of the WSDL file for a synchronousweb service (110) occurs when the synchronous web service (110)registers in the directory (114) of the integration services network(106), or “on the fly,” that is, the original WSDL file is stored in theintegration services network (106) until a user indicates interest inusing the synchronous web service (110), at which time a translated WSDLfile is generated and distributed to the user. When a requestorindicates interest in using the synchronous web service (110), theintegration services network (106) asks the requestor whether therequestor would like to use the web service (110) synchronously orasynchronously. If the requestor selects asynchronous use, thetranslated WSDL file is supplied to the requestor, where the translatedWSDL file is used to generate the necessary client code. Otherwise, theoriginal WSDL file published by the web service (110) is provided to therequestor. In one implementation, the original WSDL file may be modifiedsuch that the synchronous web service (110) is invoked through theintegration services network (106), for example, by modifying thesynchronous web service's URL in the WSDL to point to the address of theintegration services network (106). Table 1 below shows an exemplarysynchronous WSDL file, and Table 2 shows a corresponding translated WSDLfile for asynchronous consumption, for an exemplary web service“WeatherService” that provides weather information. Line numbers havebeen added on the left hand side of Tables 1 and 2 in order tofacilitate the explanation below, and do not form part of the originalWSDL file or the translated WSDL file.

TABLE 1 1) <?xml version=″1.0″?> 2) <definitions name=″WeatherService″3)   targetNamespace=″http://www.example.com/weather″ 4)  xmlns:tns=″http://www.example.com/weather″ 5)  xmlns:xsd=″http://www.w3.org/2001/XMLSchema″ 6)  xmlns:soap=″http://schemas.xmlsoap.org/wsdl/soap/″ 7)  xmlns=″http://schemas.xmlsoap.org/wsdl/″> 8)   <types> 9)     <schema10)       xmlns=″http://www.w3.org/2001/XMLSchema″ 11)  targetNamespace=″http://www.example.com/weather″> 12)      <complexType name=″weatherReport″> 13)         <sequence> 14)          <element name=″time″ type=″xsd:dateTime″/> 15)          <element name=″temperature″ type=″xsd:int″/> 16)          <element name=″humidity″ type=″xsd:int″/> 17)          <element name=″wind″ type=″xsd:string″/> 18)        </sequence> 19)       </complexType> 20)     </schema> 21)  </types> 22)   <message name=″getWeatherRequest″> 23)     <partname=″zipcode″ type=″xsd:string″/> 24)   </message> 25)   <messagename=″getWeatherResponse″> 26)     <part name=″return″type=″tns:weatherReport″/> 27)   </message> 28)   <portTypename=″publicWeatherPort″> 29)     <operation name=″getWeather″> 30)      <input message=″tns:getWeatherRequest″/> 31)       <outputmessage=″tns:getWeatherResponse″/> 32)     </operation> 33)  </portType> 34)   <binding name=″weatherSOAPBinding″type=″tns:publicWeatherPort″> 35)     <soap:binding style=″rpc″transport=″http://schemas.xmlsoap.org/soap/http″/> 36)     <operationname=″getWeather″> 37)       <soap:operation soapAction=″″/> 38)      <input> 39)         <soap:body use=″encoded″namespace=http://www.example.com/weatherencodingStyle=”http://schemas.xmlsoap.org/soap/encoding/”/> 40)      </input> 41)       <output> 42)         <soap:body use=″encoded″namespace=http://www.example.com/weatherencodingStyle=”http://schemas.xmlsoap.org/soap/encoding/”/> 43)      </output> 44)     </operation> 45)   </binding> 46)   <servicename=″WeatherService″> 47)     <port name=″weatherSOAPPort″binding=″tns:weatherSOAPBinding″> 48)       <soap:addresslocation=″http://services.example.com/soap/weather″/> 49)     </port>50)   </service> 51) </definitions>

As can be seen in Table 1, the original WSDL file contains a types part(lines 8-21), a message part (lines 22-27), a port type part (lines28-33), a bindings part (lines 34-45), and a service part (lines 46-50).

The type part of the WSDL file defines a data structure called“WeatherReport” (line 12). The WeatherReport data structure containsfour data elements: time, temperature, humidity, and wind (lines 13-18).

The message part of the WSDL file defines messages that will be sent toand from the web service. The first message is a request message,getWeatherRequest (line 22), which has one part containing a string zipcode (line 23). The second message is a response message,getWeatherResponse (line 25) that will be sent back and has one partcalled “return” (line 26) of the type WeatherReport. Thus, the responsewill contain the four elements defined above in the WeatherReport datastructure.

The port type part of the WSDL file defines how the messages will begrouped together. In this example, an operation, getWeather (line 29)consists of an input message getWeatherRequest (line 30) and an outputmessage getWeatherResponse (line 31), which were both described above.In a real world scenario, there would typically be many differentoperations, each of which has one input message and one output message.However, it should be noted that the WSDL format also fully allowsoperations that have only an input message but no output message andvice versa.

The bindings part of the WSDL file defines the protocol binding for theport, i.e., the publicWeatherPort (line 34). In this example, thebinding is a SOAP RPC style (line 35), which occurs over HTTP (line 35).No SOAP action is needed (line 37). The input and output use SOAPencoded style (lines 39 and 42), as required by RPC interactions.

Finally, the services part of the WSDL file defines how the web serviceis exposed to the outside world in terms of addressing. In this example,there is one port, weatherSOAPPort (line 47) with the addresshttp://services.example.com/soap/weather (line 48).

When the synchronous WSDL file in Table 1 is translated into anasynchronous format, the resulting file is the WSDL file shown in Table2 below. It should be noted that the translated WSDL file in Table 2 issimply an example. Other similar formats and content are also possible.

TABLE 2 1) <?xml version=″1.0″ encoding=″UTF-8″?> 2) <definitions 3)  targetNamespace=″http://www.example.com/weather″ 4)  xmlns:gcPoll=″http://grandcentral.com/schemas/poll/v1″ 5)  xmlns:soap=″http://schemas.xmlsoap.org/wsdl/soap/″ 6)  xmlns:enc=″http://schemas.xmlsoap.org/soap/encoding/″ 7)  xmlns:tns=″http://www.example.com/weather″ 8)  xmlns:xsd=″http://www.w3.org/2001/XMLSchema″ 9)   xmlns:gcPmark=  ″http://grandcentral.com/schemas/postmark/v1″ 10)  xmlns=″http://schemas.xmlsoap.org/wsdl/″> 11)   <types> 12)    <schema 13)   targetNamespace=″http://www.example.com/weather″ 14)      xmlns=″http://www.w3.org/2001/XMLSchema″> 15)       <complexTypename=″weatherReport″> 16)         <sequence> 17)           <elementname=″time″ type=″xsd:dateTime″/> 18)           <elementname=″temperature″ type=″xsd:int″/> 19)           <elementname=″humidity″ type=″xsd:int″/> 20)           <element name=″wind″type=″xsd:string″/> 21)         </sequence> 22)       </complexType> 23)    </schema> 24)     <xsd:schema 25)      xmlns:xsd=″http://www.w3.org/2001/XMLSchema″ 26)      targetNamespace= ″http://grandcentral.com/schemas/postmark/v1″>27)       <xsd:complexType name=″postmarkType″> 28)        <xsd:sequence> 29)           <xsd:element minOccurs=″0″name=″session″ nillable=″true″ type=″xsd:string″/> 30)          <xsd:element minOccurs=″0″ name=″token″ nillable=″true″type=″xsd:string″/> 31)           <xsd:element minOccurs=″0″ name=″call″nillable=″true″ type=″xsd:string″/> 32)         </xsd:sequence> 33)      </xsd:complexType> 34)     </xsd:schema> 35)   </types> 36)  <message name=″getWeatherRequest″> 37)     <part name=″zipcode″type=″xsd:string″/> 38)   </message> 39)   <messagename=″postmarkResponsen″> 40)     <part name=″postmark″type=″gcPmark:postmarkType″/> 41)   </message> 42)    <messagename=″getMessageBySession″> 43)     <part name=″session″type=″xsd:string″/> 44)   </message> 45)   <messagename=″getMessageByTopic″> 46)     <part name=″topic″ type=″xsd:string″/>47)   </message> 48)   <message name=″getMessageByToken″> 49)     <partname=″token″ type=″xsd:string″/> 50)   </message> 51)   <messagename=″getWeatherResponse″> 52)     <part name=″return″type=″tns:weatherReport″/> 53)   </message> 54)   <messagename=″acknowlegeRequest″> 55)     <part name=″token″ type=″xsd:string″/>56)   </message> 57)   <message name=″acknowlegeResponse″> 58)  </message> 59)   <portType name=″postpublicWeatherPort″> 60)    <operation name=″getWeather″> 61)       <inputmessage=″tns:getWeatherRequest″/> 62)       <outputmessage=″tns:postmarkResponse″/> 63)     </operation> 64)   </portType>65)   <portType name=″pollpublicWeatherPort″> 66)     <operationname=″pollGetWeatherBySession″> 67)       <inputmessage=″tns:getMessageBySession″/> 68)       <outputmessage=″tns:getWeatherResponse″/> 69)     </operation> 70)    <operation name=″pollGetWeatherByTopic″> 71)       <inputmessage=″tns:getMessageByTopic″/> 72)       <outputmessage=″tns:getWeatherResponse″/> 73)     </operation> 74)    <operation name=″pollGetWeatherByToken″> 75)       <inputmessage=″tns:getMessageByToken″/> 76)       <outputmessage=″tns:getWeatherResponse″/> 77)     </operation> 78)    <operation name=″acknowledge″> 79)       <inputmessage=″tns:acknowlegeRequest″/> 80)       <outputmessage=″tns:acknowlegeResponse″/> 81)     </operation> 82)  </portType> 83)   <binding name=″PostWeatherSOAPBinding″type=″tns:postpublicWeatherPort″> 84)     <soap:binding style=″rpc″transport=″http://schemas.xmlsoap.org/soap/http″/> 85)     <operationname=″getWeather″> 86)       <soap:operation soapAction=″″/> 87)      <input> 88)         <soap:body use=″encoded″encodingStyle=”http://schemas.xmlsoap.org/soap/encoding/”namespace=″http://www.example.com/weather″/> 89)       </input> 90)      <output> 91)         <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 92)namespace=″http://grandcentral.com/schemas/postmark/v1″/> 93)      </output> 94)     </operation> 95)   </binding> 96)   <bindingname=″PollWeatherSOAPBinding″ type=″tns:pollpublicWeatherPort″> 97)    <soap:binding style=″rpc″transport=″http://schemas.xmlsoap.org/soap/http″/> 98)     <operationname=″pollGetWeatherBySession″> 99)       <soap:operationsoapAction=″″/> 100)       <input> 101)         <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 102)namespace=″http://www.example.com/weather″/> 103)       </input> 104)      <output> 105)         <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″namespace=″http://www.example.com/weather″/> 106)       </output> 107)    </operation> 108)     <operation name=″pollGetWeatherByTopic″> 109)      <soap:operation soapAction=″″/> 110)       <input> 111)        <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 112)  namespace=″http://www.example.com/weather″/> 113)       </input> 114)      <output> 115)         <soap:body use=″encoded″encodingStyle=”http://schemas.xmlsoap.org/soap/encoding/”namespace=″http://www.example.com/weather″/> 116)       </output> 117)    </operation> 118)     <operation name=″pollGetWeatherByToken″> 119)      <soap:operation soapAction=″″/> 120)       <input> 121)        <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 122)  namespace=″http://www.example.com/weather″/> 123)       </input> 124)      <output> 125)         <soap:body use=″encoded″encodingStyle=”http://schemas.xmlsoap.org/soap/encoding/”namespace=″http://www.example.com/weather″/> 126)       </output> 127)    </operation> 128)     <operation name=″acknowledge″> 129)      <soap:operation soapAction=″″/> 130)       <input> 131)        <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 132)  namespace=″http://grandcentral.com/schemas/poll/v1″/> 133)      </input> 134)       <output> 135)         <soap:body use=″encoded″encodingStyle=″http://schemas.xmlsoap.org/soap/encoding/″ 136)namespace=″http://grandcentral.com/schemas/poll/v1″/> 137)      </output> 138)     </operation> 139)   </binding> 140)   <servicename=″WeatherService″> 141)     <port name=″postweatherSOAPPort″binding=″tns:PostWeatherSOAPBinding″> 142)       <soap:address location=″http://pop.grandcentral.com/post/soaprpc/example.com/weather″/> 143)    </port> 144)     <port name=″pollweatherSOAPPort″binding=″tns:PollWeatherSOAPBinding″> 145)       <soap:addresslocation=″http://pop.grandcentral.com/poll/soaprpc″/> 146)     </port>147)   </service> 148) </definitions>

Just like the synchronous WSDL file shown in Table 1, the translatedasynchronous WSDL file contains a types part (lines 11-35), a messagepart (lines 36-58), a port type part (lines 59-82), a bindings part(lines 83-139), and a service part (lines 140-147).

In the types part, the WeatherReport data structure is preserved fromthe original WDSL file (lines 15-22). A “postmarkType” data structurehas been added (lines 27-33), which describes a postmark that isreturned when a request is asynchronously posted to the integrationservices network (106). The postmark is used during the pollingdescribed above with reference to FIG. 2 and FIG. 3, so that theintegration services network (106) knows which response to look forduring the polling operation. Three identifiers are provided in thepostmark: a session (line 29), a token (line 30), and a call (line 31).

As can be seen, the message part in the translated WSDL file in Table 2contains more messages than the original WSDL file. Just like in theoriginal WSDL file, there is a getWeatherRequest message, where a zipcode can be submitted (lines 36-38). The next message, postmarkResponse,is a response message containing a postmark (lines 39-41). The nextmessage, getMessageBySession, describes a way to poll using a sessionidentifier (lines 42-44). getMessageByTopic, describes a way to pollusing a topic (lines 45-47). getMessageByToken, describes a way to pollusing a token (lines 48-50). getWeatherResponse (lines 51-53) is, justlike in Table 1, a message that contains the response from the webservice. Finally, there are a couple of additional messages foracknowledging successful retrieval of messages from the integrationservices network (106) (lines 54-58).

The port type part contains a post port (lines 59-64) and a poll port(lines 65-82), since both a post port and a poll port is needed forasynchronous operation, as described above with reference to FIG. 3. Thepost port has an operation called getWeather (line 60), and the inputis, just like in the original WSDL file, getWeatherRequest (line 61),but instead of getting the getWeatherResponse, a postmark response isgiven back (line 62). The poll port contains three different pollingoptions: polling by session identifier (lines 66-69), polling by topic(lines 70-73), and polling by token (lines 74-77). As was describedabove, both the token for the response message and session were returnedin the postmark. The topic would potentially be included in the requestthat was sent to the web service, similar to a subject line of amessage. The token guarantees that the exact message will be obtained. Asession can contain multiple messages, so polling by session will returnone or more of multiple active messages related to a particular session.A topic is similar to a session in that the topic can also be present inmultiple messages, and that polling by topic may return one or moremessages related to the particular topic. When polling by one of thesemethods, the getWeatherResponse is returned, that is, thegetWeatherResponse message is now returned asynchronously from thegetWeatherRequest message, whereas in the original WSDL file in Table 1,the response would have been returned synchronously. The acknowledgeoperation (lines 78-81) is a way for the web service to tell theintegration services network (106) that the message has been receivedand can be deleted from the delivery queue in the integration servicesnetwork.

The bindings section is similar to the original WSDL file. As the readerskilled in the art will realize, there are other bindings than SOAP thatcould be used, for example, an HTTP Get binding, and that SOAP is onlyused herein by way of example for illustrative purposes. Finally, theservice part has two ports: a post port, postweatherSOAPPort (line 141),and a poll port, pollweatherSOAPPort (line 144), that each has their ownURL.

As the reader skilled in the art will realize, a correspondingtranslation can be made from a WSDL for an asynchronous web service intoa WSDL for a synchronous client. However, at the present timeasynchronous web services are far less common than synchronous webservices, so the vast majority of WSDL conversions would occur in themanner described above. In doing such a translation, however, it isnecessary to know which combinations of asynchronous operations can becombined into a single synchronous operation. Thus, the translationrequires either some convention on naming of operations, in order to beperformed completely automatically, or some interaction from a userindicating how asynchronous operations pair up to form a synchronousoperation. Such a mapping can, for example, be accomplished with amapping tool with which a user can select operations out of renderedWSDL information to indicate pairing into synchronous operations. Themapping can, for example, be done at the time of registering the webservice with the integration services network (106).

In both cases, the directory in the integration services network can,for example, store templates for the conversions or translations thatare later modified for the specific instance of a needed conversion. Forexample, a template can contain the parts of Table 2 above that areindependent of the original WSDL file, such as the postmark datastructure and all the messages that define polling and acknowledging.The template can have sections in which parts of the original WSDL aresubstituted into the template. Templates, however, are just oneapproach, and there can be other equally useful approaches as well.

The invention can be implemented in digital electronic circuitry, or incomputer hardware, firmware, software, or in combinations of them.Apparatus of the invention can be implemented in a computer programproduct tangibly embodied in a machine-readable storage device forexecution by a programmable processor; and method steps of the inventioncan be performed by a programmable processor executing a program ofinstructions to perform functions of the invention by operating on inputdata and generating output. The invention can be implementedadvantageously in one or more computer programs that are executable on aprogrammable system including at least one programmable processorcoupled to receive data and instructions from, and to transmit data andinstructions to, a data storage system, at least one input device, andat least one output device. Each computer program can be implemented ina high-level procedural or object-oriented programming language, or inassembly or machine language if desired; and in any case, the languagecan be a compiled or interpreted language. Suitable processors include,by way of example, both general and special purpose microprocessors.Generally, a processor will receive instructions and data from aread-only memory and/or a random access memory. Generally, a computerwill include one or more mass storage devices for storing data files;such devices include magnetic disks, such as internal hard disks andremovable disks; magneto-optical disks; and optical disks. Storagedevices suitable for tangibly embodying computer program instructionsand data include all forms of non-volatile memory, including by way ofexample semiconductor memory devices, such as EPROM, EEPROM, and flashmemory devices; magnetic disks such as internal hard disks and removabledisks; magneto-optical disks; and CD-ROM disks. Any of the foregoing canbe supplemented by, or incorporated in, ASICs (application-specificintegrated circuits).

To provide for interaction with a user, the invention can be implementedon a computer system having a display device such as a monitor or LCDscreen for displaying information to the user and a keyboard and apointing device such as a mouse or a trackball by which the user canprovide input to the computer system. The computer system can beprogrammed to provide a graphical user interface through which computerprograms interact with users.

A number of implementations of the invention have been described.Nevertheless, it will be understood that various modifications may bemade without departing from the spirit and scope of the invention. Forexample, the operations of the integration services network can beperformed either on the requestors' computer systems, or on the webservice's, respectively, and similar results could be achieved. However,this would place larger requirements on the requestors and web services,respectively, which can be avoided with the approaches described above,where the requestors and web services do not need to have anyinformation about the configuration of the respective partners withwhich they communicate. In this case, the integration services network(106) acts a shared service available on the public Internet to therequestors and web services. Accordingly, other embodiments are withinthe scope of the following claims.

What is claimed is:
 1. A computer-implemented method for facilitatingaccess to one or more services in a network environment, the methodcomprising: receiving, at a host, a request from a client machine incommunication with the host over a network; obtaining, at the host, anasynchronous service description file indicating one or moreasynchronous communication techniques configured to be performed by amachine to access or communicate with a service over the network, theasynchronous service description file being a conversion of asynchronous service description file indicating one or more synchronouscommunication techniques for accessing or communicating with asynchronous service; and providing, to the client machine, theasynchronous service description file.
 2. The computer-implementedmethod of claim 1, further comprising: obtaining permission informationindicating a permission of the client machine to access one or moreservices.
 3. The computer-implemented method of claim 2, whereinobtaining the permission information includes: performing one or moresecurity management operations in association with the client machine orwith a user of the client machine.
 4. The computer-implemented method ofclaim 3, wherein the security management operations include one or moreof: authentication, authorization, security policy enforcement,decryption, and validation of a digital signature.
 5. Thecomputer-implemented method of claim 2, wherein obtaining the permissioninformation includes: retrieving the permission information from apolicy repository.
 6. The computer-implemented method of claim 1,further comprising: providing, at the host, one or more interfaces forcommunications between the client machine and the synchronous serviceover the network, the one or more interfaces permitting: synchronouscommunications with the synchronous service in accordance with thesynchronous service description file, and asynchronous communicationswith the client machine in accordance with the asynchronous servicedescription file.
 7. The computer-implemented method of claim 1, furthercomprising: receiving a message from the client machine at anasynchronous interface; processing the message at the host; andproviding the processed message to the synchronous service at asynchronous interface.
 8. The computer-implemented method of claim 7,wherein providing the processed message to the synchronous serviceincludes: sending the processed message in response to polling by thesynchronous service.
 9. The computer-implemented method of claim 1,further comprising: receiving a message from the synchronous service ata synchronous interface; processing the message at the host; andproviding the processed message to the client machine at an asynchronousinterface.
 10. The computer-implemented method of claim 1, whereinobtaining the asynchronous service description file includes: convertingthe synchronous service description file to the asynchronous servicedescription file.
 11. The computer-implemented method of claim 1,wherein obtaining the asynchronous service description file includes:retrieving the asynchronous service description file from a storagemedium accessible at the host.
 12. The computer-implemented method ofclaim 1, wherein the service description files are in web servicedescription language (WSDL) format.
 13. A computer-implemented methodfor facilitating access to one or more services in a networkenvironment, the method comprising: receiving, at a host, a request froma client machine in communication with the host over a network;obtaining, at the host, an asynchronous service description fileincluding one or more asynchronous instructions to be performed by amachine to access a service over the network, the asynchronous servicedescription file being a translation of a synchronous servicedescription file including one or more synchronous instructions foraccessing a synchronous service; and providing, to the client machine,the asynchronous service description file.
 14. A computer-implementedmethod for facilitating access to one or more services in a networkenvironment, the method comprising: providing, at a host, anasynchronous service description file indicating one or moreasynchronous instructions to be performed by a client machine to accessa service over a network, the asynchronous service description filebeing a conversion of a synchronous service description file indicatingone or more synchronous instructions for accessing a synchronousservice; and managing, at the host, communication between the clientmachine and the synchronous service, the host configured to communicateasynchronously with the client machine in accordance with theasynchronous service description file, the host configured tocommunicate synchronously with the synchronous service in accordancewith the synchronous service description file.
 15. Thecomputer-implemented method of claim 14, further comprising: accessing adirectory stored on a storage medium, the directory mapping an identityfor each of a plurality of users to a policy framework defining accessinformation relating to one or more services.
 16. Thecomputer-implemented method of claim 15, further comprising: mediatingpolicy differences among the plurality of users and the one or moreservices according to the policy framework.
 17. A computer-implementedmethod for facilitating access to services in a network environment, themethod comprising: receiving, at a host, a request from a client machinein communication with the host over a network; obtaining, at the host: afirst asynchronous service description file indicating one or moreasynchronous communication techniques configured to be performed by amachine, the first asynchronous service description file being aconversion of a first synchronous service description file indicatingone or more synchronous communication techniques for accessing orcommunicating with a synchronous service, and a second synchronousservice description file indicating one or more synchronouscommunication techniques configured to be performed by a machine, thesecond synchronous service description file being a conversion of asecond asynchronous service description file indicating one or moreasynchronous communication techniques for accessing or communicatingwith an asynchronous service; and providing, to the client machine, oneor both of the first asynchronous service description file and thesecond synchronous service description file.
 18. A computer-implementedmethod for facilitating access to one or more services in a networkenvironment, the method comprising: receiving, at a host, a request froma client machine in communication with the host over a network;obtaining, at the host, a synchronous service description fileindicating one or more synchronous communication techniques configuredto be performed by a machine to access or communicate with a serviceover the network, the synchronous service description file being aconversion of an asynchronous service description file indicating one ormore asynchronous communication techniques for accessing orcommunicating with an asynchronous service; and providing, to the clientmachine, the synchronous service description file.
 19. A system forfacilitating access to one or more services in a network environment,the system comprising: software stored on a non-transitory storagemedium for execution by one or more processors, the software operable tocause: obtaining, at a host, an asynchronous service description fileindicating one or more asynchronous communication techniques configuredto be performed by a machine to access or communicate with a serviceover a network, the asynchronous service description file being aconversion of a synchronous service description file indicating one ormore synchronous communication techniques for accessing or communicatingwith a synchronous service, and providing, to the client machine, theasynchronous service description file.
 20. Apparatus for facilitatingaccess to one or more services in a network environment, the apparatuscomprising: a storage medium storing an asynchronous service descriptionfile indicating one or more asynchronous instructions to be performed bya client machine to access a service over a network, the asynchronousservice description file being a conversion of a synchronous servicedescription file indicating one or more synchronous instructions foraccessing a synchronous service; and one or more processors of a hostoperable to manage communication between the client machine and thesynchronous service, the host configured to communicate asynchronouslywith the client machine in accordance with the asynchronous servicedescription file, the host configured to communicate synchronously withthe synchronous service in accordance with the synchronous servicedescription file.
 21. The apparatus of claim 20, further comprising: anasynchronous interface through which the client is capable ofcommunicating with the host over the network, and a synchronousinterface through which the synchronous service is capable ofcommunicating with the host over the network.
 22. A computer programproduct comprising instructions to be executed by one or more processorswhen retrieved from a non-transitory computer readable medium, theinstructions configured to cause: providing, at a host, an asynchronousservice description file indicating one or more asynchronousinstructions to be performed by a client machine to access a serviceover a network, the asynchronous service description file being aconversion of a synchronous service description file indicating one ormore synchronous instructions for accessing a synchronous service; andmanaging, at the host, communication between the client machine and thesynchronous service, the host configured to communicate asynchronouslywith the client machine in accordance with the asynchronous servicedescription file, the host configured to communicate synchronously withthe synchronous service in accordance with the synchronous servicedescription file.